The use of coal dust and other powdered solids as fuel has long been known (U.S. Pat. No. 1,926,304, Sept. 12, 1933; Power, Volume 80, pp. 258 and 259, May 1936; Power, March 1974; "Mechanical Engineering", page 55, March 1976; U.S. Pat. No. 3,950,143, Apr. 13, 1976). The adaptation of specific powdered solids as fuels for single- or variable-speed engines or for furnaces has not been fully developed.
The cost of energy (dollars per million BTU's) from the burning of corn and wheat is comparable to that from oil, gasoline and liquified gas, but much higher (two to three times) than that from coal. Grain dust (emissions) represents about 0.4 percent of the total U.S. grain production (1.6 million metric tons out of 414 million metric tons). The 1.6 million metric tons of grain dust (emissions) at 8000 BTU/lb (dry) represents only 0.13 percent of the energy content of the 800 metric tons of coal, at 12,000 BTU/lb, to be produced in the U.S. in 1980. The available grain dust emissions are projected as a viable fuel source for the approximately 8,000 country, inland terminal and port terminal grain facilities located throughout the United States. They provide a safe, nonpolluting way to eliminate a very dangerous pollution source. At an essentially zero resource cost, they provide a substantial reduction in grain-elevator heating and/or power costs.